JP4093369B2 - Glass fiber for long fiber reinforced polypropylene resin molding material and long fiber reinforced polypropylene resin molding material - Google Patents

Description

  The present invention relates to a glass fiber for a long fiber reinforced polypropylene resin molding material and a long fiber reinforced polypropylene resin molding material for obtaining a polypropylene resin molded product having excellent mechanical strength.

  Polypropylene resin is a relatively inexpensive and lightweight material, and because of its ease of molding, it is a general-purpose material used in a wide range of fields such as automobile parts, home appliances, food packaging films, toys, and miscellaneous goods. Since its mechanical properties, particularly impact resistance and heat resistance, are poor, its use has been limited.

  Various studies have been made to improve the mechanical properties of polypropylene resins. For example, by filling glass fibers or fillers into polypropylene resins to make composite materials, the mechanical properties can be dramatically improved. it can. For example, a material obtained by adjusting a plastic material such as a polypropylene resin in combination with glass fiber and integrating the material is called FRTP (Fiber Reinforced Thermo Plastics), which is a material that is lightweight and excellent in mechanical strength.

These materials are required to improve the impregnation property of the polypropylene resin into the glass fiber bundle and not to generate voids between the glass fibers. For example, Patent Document 1 listed below discloses a polyolefin resin having a low viscosity and a low molecular weight. As a matrix resin, impregnating the polyolefin resin into the glass fiber by impregnating the polyolefin resin while bringing the glass fiber bundle into contact with the protrusions or rollers provided inside the impregnation die and opening the glass fiber bundle A manufacturing method for obtaining a highly fiber-reinforced structure is disclosed.
Japanese Patent Publication No. 63-37694

  The method for producing a fiber reinforced structure disclosed in Patent Document 1 uses a low viscosity and low molecular weight matrix resin to bring a glass fiber bundle into contact with a protrusion or a roller to apply tension to open the glass fiber. However, for example, in the case of glass fiber having a strong bundling property, the above-mentioned protrusions and rollers cannot sufficiently open the fiber, and it may be difficult to impregnate the matrix resin. On the other hand, when a glass fiber bundle having weak convergence is used, when the fiber is opened by the protrusions or rollers, a part of the single fiber constituting the glass fiber bundle is cut by friction and becomes fluff. There is a problem that the nozzle is clogged and the nozzle is blocked, the tensile resistance of the glass fiber bundle is increased, the glass fiber bundle is broken, and the productivity is lowered.

  In addition, even if the production rate is reduced or the production of fluff is reduced by reducing the tension or the like, the glass fiber having poor convergence is weak in film strength or adhesive strength, so that the resulting propylene resin The mechanical properties of the molded product were inferior.

  The present invention has been made in view of the above problems, and its purpose is to prevent generation of fluff and breakage of a glass fiber bundle that occurred when producing a long fiber reinforced polypropylene resin molding material, Furthermore, the glass fiber for the long fiber reinforced polypropylene resin molding material and the long fiber reinforced polypropylene which can improve the dispersibility and impregnation of the glass fiber in the matrix resin and improve the mechanical properties of the polypropylene resin molded product. The object is to provide a resin molding material.

  As a result of conducting various studies to achieve the above object, the present inventors have given a glass fiber a sizing agent containing a silane coupling agent and a polypropylene resin having specific physical properties. It is possible to increase the glass fiber's bundling property, make it less likely to generate fuzz and break the glass fiber, and obtain a glass fiber having excellent dispersibility and impregnation of the glass fiber in the matrix resin. The headline and the present invention were completed.

That is, the glass fiber for long fiber reinforced polypropylene resin molding material of the present invention has a silane coupling agent (A), a polypropylene resin (B) having a weight average molecular weight of 10,000 to 20,000 , and a weight average molecular weight of 23. A sizing agent containing a polypropylene resin (C) of 5,000 to 50,000, and having a mass ratio of 20 to 80:80 to 20 of the polypropylene resin (B) and the polypropylene resin (C). Is characterized by being focused.

Further , the polypropylene resin (B) having a weight average molecular weight of 10,000 to 20,000 and the polypropylene resin (C) having a weight average molecular weight of 23,000 to 50,000 contained in the sizing agent are in a mass ratio. It is preferable that it is 20-70: 80-30.

Further, the polypropylene resin (B) having a weight average molecular weight of 10,000 to 20,000 is preferably an acid-modified polypropylene resin and an acid value of 40 to 50 (mgKOH / g).

  The polypropylene resin (C) having a weight average molecular weight of 23,000 to 50,000 is preferably an acid-modified polypropylene resin and an acid value of 10 to 50 (mgKOH / g).

  On the other hand, in the long fiber reinforced polypropylene resin molding material of the present invention, each single fiber of the glass fiber for long fiber reinforced polypropylene resin molding material prepared as described above is composed of polypropylene resin (D) and acid-modified polypropylene resin ( It is characterized by being contained in the matrix resin comprising E) in parallel in substantially the same length and in the same direction.

  The long fiber reinforced polypropylene resin molding material using the glass fiber for long fiber reinforced polypropylene resin molding material of the present invention can provide a polypropylene resin molded article having excellent dispersion of glass fibers and excellent mechanical properties.

According to the glass fiber for a long fiber reinforced polypropylene resin molding material of the present invention, a silane coupling agent (A) as a glass fiber sizing agent, a polypropylene resin (B) having a weight average molecular weight of 10,000 to 20,000 , and By using a composition containing a polypropylene resin (C) having a weight average molecular weight of 23,000 to 50,000, it is possible to maintain openability of the glass fiber while maintaining excellent converging properties. it can.

  And the glass fiber for long fiber reinforced polypropylene resin molding material of the present invention is contained in a matrix resin made of polypropylene resin, and is contained in parallel in substantially the same length and in the same direction. Can produce a polypropylene resin molded article having a small amount of fluff generated during production and transportation, good glass fiber dispersion, and excellent mechanical properties.

  The glass fiber sizing agent in the present invention contains a silane coupling agent (A) and a polypropylene resin.

  The silane coupling agent (A) used in the sizing agent of the present invention is preferably an aminosilane having an amino group, and the amino group of the aminosilane is more preferably a primary and / or secondary amino group. Preferable specific examples include γ-aminopropyltriethoxysilane, N-β- (aminoethyl) -γ-aminopropyltrimethoxysilane, N-β- (aminoethyl) -N′-β- (aminoethyl)- Examples thereof include aminosilanes such as γ-aminopropyltrimethoxysilane and γ-anilinopropyltrimethoxysilane.

  The aminosilane is preferable because the reactivity with the polypropylene resin in the sizing agent is particularly high, so that the sizing property of the fibers can be improved, the adhesiveness with the matrix resin can be improved, and the mechanical properties can be improved. Among them, γ-aminopropyltriethoxysilane is preferable because the color tone of the polypropylene resin molded article is good.

  The polypropylene resin used for the sizing agent in the present invention may be a polypropylene homopolymer, but an ethylene-propylene random copolymer, an ethylene-propylene block copolymer, an ethylene-α-propylene copolymer, a propylene-α- It may be a copolymer such as a propylene copolymer.

  The polypropylene resin used for the sizing agent of the present invention is more preferably an acid-modified polypropylene resin.

  The acid-modified polypropylene resin is, for example, converted into a sulfone group after chlorsulfonating the polypropylene resin, or directly sulfonated, or copolymerizing a polymerizable unsaturated carboxylic acid compound or a derivative thereof with polyolefin at the time of producing the polypropylene resin. Alternatively, it can be obtained by a method such as graft polymerization of an addition polymerizable unsaturated carboxylic acid compound or a derivative thereof to a polypropylene resin.

  In the present invention, a sulfonated polypropylene resin is more preferable. Examples of the sulfonated polypropylene resin include those obtained by reacting a polypropylene resin with chlorine and sulfur dioxide or chlorosulfonic acid to chlorosulfonate, and changing the sulfonate to a sulfone group, or directly sulfonated polypropylene resin. Is mentioned.

  Also, a polypropylene homopolymer modified with an unsaturated carboxylic acid or a derivative thereof, or an acid-modified polypropylene resin which is a copolymer can be used. Examples of the acid-modified polypropylene resin include those obtained by graft-polymerizing an unsaturated carboxylic acid or a derivative thereof on polypropylene, or one or two or more selected from propylene and an unsaturated carboxylic acid or a derivative thereof in a random or block manner. Polymerized products, or those obtained by graft polymerization of an unsaturated carboxylic acid or a derivative thereof to these polymers may be mentioned.

  Examples of the unsaturated carboxylic acid used for acid modification of the polypropylene resin include maleic acid, fumaric acid, itaconic acid, acrylic acid, and methacrylic acid. Examples of the unsaturated carboxylic acid derivative include anhydrides, esters, amides, imides, and metal salts of these acids. Specific examples thereof include maleic anhydride, itaconic anhydride, methyl acrylate, ethyl acrylate, butyl acrylate, glycidyl acrylate, methyl methacrylate, ethyl methacrylate, glycidyl methacrylate, monoethyl maleate, maleic acid Examples include diethyl ester, fumaric acid monomethyl ester, fumaric acid dimethyl ester, acrylamide, methacrylamide, maleic acid monoamide, maleic acid diamide, fumaric acid monoamide, maleimide, N-butylmaleimide, and sodium methacrylate.

  In the present invention, among the above unsaturated carboxylic acids and derivatives thereof, glycidyl ester of acrylic acid or methacrylic acid, or maleic anhydride is used, and a maleic anhydride is added to a polypropylene resin having ethylene and / or propylene as a main resin constituent unit. It may be acid-modified by graft polymerization of acid, or acid-modified by copolymerization of polypropylene mainly composed of ethylene and / or propylene and (meth) acrylic acid glycidyl ester or maleic anhydride. preferable.

The polypropylene resin used for the sizing agent of the present invention includes a polypropylene resin (B) having a weight average molecular weight of 10,000 to 20,000 and a polypropylene resin (C) having a weight average molecular weight of 23,000 to 50,000. It is characterized by being.

  The weight average molecular weight of the polypropylene resin (B) is more preferably 10,000 to 20,000, and the weight average molecular weight of the polypropylene resin (C) is more preferably 25,000 to 35,000.

  When the weight average molecular weight of the polypropylene resin (B) is less than 5,000, the glass fiber is easily fuzzed at the time of opening to reduce workability, and the mechanical properties are inferior, and the weight average molecular weight is 23. If it exceeds 1,000, the impregnating property with the resin will be inferior due to the decrease in the openability of the glass fiber.

  In addition, if the weight average molecular weight of the polypropylene resin (C) is less than 23,000, the glass fiber tends to become fluffy at the time of opening, and workability is inferior. If it exceeds 50,000, the focusing power of the glass fiber is too strong. Therefore, the glass fiber bundle may not be fully opened even when trying to open the fiber bundle with protrusions or rollers provided inside the impregnation die, and the unopened part of the glass fiber is not contained in the propylene resin molded product. Since it may remain as an undispersed material and the appearance of the resulting propylene resin molded product will be lost, it is not preferable.

Moreover, the polypropylene resin contained in the sizing agent requires that the polypropylene resin (B) and the polypropylene resin (C) have a mass ratio of 20 to 80:80 to 20 , and 20 to 70:80 to 30. Are preferred. If the mass ratio of the polypropylene resin (B) is less than 20, the opening of the glass fiber is deteriorated, so that the appearance of the propylene resin molded product is inferior. Since the mechanical strength of the resin molded product is inferior, it is not preferable.

The polypropylene resin (B) weight average molecular weight of 10,000 and 20,000 in the present invention, the molecular weight distribution measuring apparatus, for example, a weight average molecular weight by GPC (gel permeation chromatography) is in 10,000 to 20,000 And having a peak molecular weight of 10,000 to 20,000 is preferable, and as the polypropylene resin (C) having a weight average molecular weight of 23,000 to 50,000, a molecular weight distribution measuring device such as GPC can be used. A gel having a weight average molecular weight of 23,000 to 50,000 and a peak molecular weight of 23,000 to 50,000 by (gel permeation chromatography) is preferable.

  Moreover, when a polypropylene resin (B) is an acid-modified polypropylene resin, it is preferable that an acid value is 40-50 (mgKOH / g). When the acid value is less than 40 (mgKOH / g), the mechanical properties are inferior because the acid addition amount for bonding the glass fiber and the resin matrix is small, and when the acid value exceeds 50 (mgKOH / g), it is released. When the acid component (not grafted) reacts with the silane coupling agent, etc., the adhesion between the glass fiber and the resin matrix decreases, resulting in inferior mechanical properties and the color tone of the propylene resin molded product tends to turn yellow. This is also not preferable.

  When the polypropylene resin (C) is an acid-modified polypropylene resin, the acid value is preferably 10 to 50 (mgKOH / g). When the acid value is less than 10 (mgKOH / g), the mechanical properties are inferior because the acid addition amount for bonding the glass fiber and the resin matrix is small, and when the acid value exceeds 50 (mgKOH / g), the acid is liberated. When the acid component (not grafted) reacts with the silane coupling agent, etc., the adhesion between the glass fiber and the resin matrix is lowered, so that the mechanical strength is inferior, and the color tone of the propylene resin molded product is easily yellowed. Is also not preferable.

  Further, the sizing agent used in the present invention is an antistatic agent typified by inorganic salts such as lithium chloride and potassium iodide, and quaternary ammonium salts such as ammonium chloride type and ammonium ethosulphate type in addition to the above components. Alternatively, it may contain a side additive such as a lubricant represented by an aliphatic ester, aliphatic ether, aromatic ester or aromatic ether surfactant.

  The silane coupling agent (A) used in the sizing agent of the present invention is preferably contained in an amount of 5 to 50 parts by mass, more preferably 10 to 35 parts by mass when the solid content of the sizing agent is 100 parts by mass. is there. If it is less than 5 parts by mass, the adhesion between the glass fiber and the matrix resin is inferior, and if it exceeds 50 parts by mass, no further reinforcing effect can be expected. Furthermore, finally obtained polypropylene resin This is not preferable because the molded product is yellowed and colored.

  The polypropylene resin (B) contained in the sizing agent of the present invention is preferably contained in an amount of 20 to 70 parts by mass, more preferably 30 to 60 parts by mass when the solid content of the sizing agent is 100 parts by mass. If it is less than 20 parts by mass, the dispersibility of the glass fibers in the molded product is poor, and if it exceeds 70 parts by mass, fluffing tends to occur and the mechanical properties become low, which is not preferable.

  In addition, the polypropylene resin (C) is preferably contained in an amount of 30 to 80 parts by mass, more preferably 40 to 70 parts by mass when the solid content of the sizing agent is 100 parts by mass. When the amount is less than 30 parts by mass, fluffing tends to occur and mechanical properties are lowered, and when it exceeds 80 parts by mass, the dispersibility of the glass fibers in the molded product is poor, which is not preferable.

  Moreover, it is preferable that the auxiliary additive contained in the sizing agent is 50 parts by mass or less with respect to 100 parts by mass of the sizing agent. If the amount exceeds 50 parts by mass, the dispersibility of the glass fiber in the molded product is lowered, and the workability tends to be reduced, which is not preferable.

Sizing agent used in the present invention, a silane coupling agent within the above range as (A), the weight average molecular weight of the polypropylene resin (B) of 10,000 to 20,000, a weight average molecular weight of 23,000～50, 000 polypropylene resin (C) and, if necessary, admixtures such as those shown above, are usually mixed by mixing these components in an aqueous medium such as water. Prepared.

  The material of the glass fiber used in the present invention is not particularly limited, but the monofilament average diameter is preferably 6 to 23 μm, more preferably 10 to 17 μm. When the average diameter of the monofilament is less than 6 μm, the cost is high in obtaining a long fiber reinforced polypropylene resin molding material, which is not economically preferable. When the average diameter exceeds 23 μm, the mechanical strength of the molding material is increased. Since physical properties are inferior, it is not preferable.

  In the present invention, the glass fiber bundling treatment method using a bundling agent is not particularly limited, and may be a known treatment method such as coating by a roll coater, curtain coater, or the like, or spray coating.

  The sizing agent is preferably applied so that the solid content is 0.1 to 2 parts by mass, and preferably 0.2 to 1 part by mass, with respect to 100 parts by mass of the glass fiber and the sizing agent. It is more preferable. If the applied amount is less than 0.1 parts by mass, the glass fiber is insufficiently converged and easily fuzzed, and the adhesion between the glass fiber and the matrix resin is inferior. On the other hand, if the applied amount exceeds 2 parts by mass, the opening of the glass fibers at the time of impregnation with the matrix resin becomes insufficient, and this causes a defect due to the presence of unopened glass fibers in the matrix resin.

  The glass fiber for a long fiber reinforced polypropylene resin molding material of the present invention is preferably the above-mentioned sizing agent, in which 100 to 7,000 glass fibers are bundled, preferably 300 to 5,000 glass fibers. More preferably, it is focused. If the number is less than 100, the glass fibers tend to fluff, and yarn breakage tends to occur at the time of opening with the opening bar in the impregnation die. Furthermore, since a large number of wound bodies are required, work efficiency is inferior. If the number is more than 7000, the impregnation with the matrix resin is inferior, which is not preferable.

  As described above, the glass fiber for a long fiber reinforced polypropylene resin molding material of the present invention can be obtained.

  In addition, the above-mentioned long fiber reinforced polypropylene resin molding material glass fiber is impregnated with a matrix resin made of polypropylene resin, and each glass single fiber is contained in the matrix resin so as to be arranged substantially in the same length and in the same direction. By doing so, the long fiber reinforced polypropylene resin composition of the present invention is obtained.

  The matrix resin used in the present invention preferably contains a polypropylene resin (D) and an acid-modified polypropylene resin (E). The acid-modified polypropylene resin (E) used in the matrix resin is the sizing agent. Although the thing similar to what is contained in can be used, since the acid-modified polypropylene resin modified with unsaturated carboxylic acids, such as maleic acid and acrylic acid, has compatibility with the said sizing agent, it is more preferable.

  Acid-modified polypropylene resins that have been acid-modified with unsaturated carboxylic acids can be produced by an extrusion method in which maleic acid, acrylic acid, or the like is modified into a polyolefin resin by an extruder, or a melting method in which polymerization is performed while melting in a batch or the like in advance. Can be mentioned. Among these, in the present invention, it is preferable to use an acid-modified polypropylene resin prepared by a melting method because the mechanical properties of the obtained propylene resin molded product can be further improved.

  The polypropylene resin (D) can be appropriately mixed with known additives such as colorants, modifiers, fillers other than glass fibers, depending on the application and molding conditions. It can be kneaded and blended.

  The matrix resin used in the present invention preferably contains 98.0 to 99.0 parts by mass of the polypropylene resin (D), more preferably 98.2 to 98.6 parts by mass. . The acid-modified polypropylene resin (E) is preferably contained in an amount of 1.0 to 2.0 parts by mass, and more preferably 1.4 to 1.8 parts by mass.

  The acid-modified polypropylene resin (E) contained in the matrix resin is necessary for improving the adhesion between the matrix resin and the glass fiber and improving the mechanical properties of the propylene resin molded product. If it is less than part by mass, the effect of addition is poor. Moreover, even if the addition amount exceeds 2.0 parts by mass, an effect of a certain level or more cannot be obtained.

  The long fiber reinforced polypropylene resin molding material of the present invention provides excellent mechanical properties even when the amount of the acid-modified polyolefin resin (E) contained in the matrix resin is as small as 2.0 parts by mass or less. Can do.

  The long fiber reinforced polypropylene resin molding material of the present invention can be obtained by applying the above matrix resin to the glass fibers treated with the sizing agent.

  Examples of a method for containing glass fibers that have been bundled with a sizing agent into a matrix resin include, for example, a method called a melt impregnation method in which glass fibers are impregnated into a molten matrix resin, or a matrix resin solution that is dispersed or dissolved in a solvent such as water The glass fiber is coated and contained, and after the powdered matrix resin is applied to the glass fiber, it is heated and melted and then cooled and contained. Is preferable from the standpoint of unnecessary and cost.

  By incorporating glass fibers into the matrix resin, the long fiber reinforced polypropylene resin molding material of the present invention can be obtained. The long-fiber fiber-reinforced polypropylene resin molding material of the present invention contains each glass single fiber in the matrix resin with substantially the same length and arranged in parallel in the same direction, preferably in the form of a wire or pellet It is. The fact that glass single fibers are substantially the same length and contained in parallel in the same direction means that most of glass single fibers are arranged in parallel substantially in parallel in the same direction. This means that the single fibers may be partially curved or entangled with each other.

  Further, in the long fiber reinforced polypropylene resin molding material of the present invention, since the matrix resin is impregnated between the glass single fibers, the glass fibers exhibit high dispersibility during molding and have excellent mechanical properties. A polypropylene resin molded product can be obtained.

  The content ratio of the glass fiber in the long fiber reinforced polypropylene resin molding material in the present invention is not particularly limited, but in order to bring out the effects of the present invention remarkably, when the entire molding material is 100 parts by mass, it is preferably 25 to 70. It is 40 mass parts more preferably 40 mass parts. When the glass fiber content is less than 25 parts by mass, the reinforcing effect by the glass fiber cannot be obtained, and when it exceeds 70 parts by mass, the weight of the long fiber reinforced polypropylene resin molding material is not preferable.

  Moreover, the length of the glass fiber in the long fiber reinforced polypropylene resin molding material of this invention is although it does not specifically limit, Preferably it is 3-30 mm, More preferably, it is 6-20 mm. When the length is less than 3 mm, fluff is likely to occur during the production of the wire-like or pellet-like material of the long fiber reinforced polypropylene resin molding material, and the effect of fiber reinforcement is difficult to be exhibited. On the other hand, when the length exceeds 30 mm, there is a possibility of causing dispersion of glass fibers and a decrease in fluidity when molding by injection molding.

  The average diameter of the long fiber reinforced polypropylene resin molding material of the present invention is preferably 0.3 to 3.4 mm, more preferably 1 to 2.6 mm. In the present invention, since a specific glass fiber sizing agent is used, the problem of workability when producing a polyolefin resin-forming material containing glass fibers having a relatively thin average diameter is improved. When the thickness is less than 0.3 mm, the bulk density of the molding material is reduced, and the transportability is inferior. On the other hand, if the average diameter exceeds 3.4 mm, the dispersibility of the glass fiber is inferior when molding by injection molding, which is not preferable.

  The glass fiber for long fiber reinforced polypropylene resin molding material of the present invention and the long fiber reinforced polypropylene resin molding material, for example, can be obtained through the following steps.

  That is, the glass melted in the electric furnace is accommodated in a bushing, dropped by its own weight from an orifice formed at the bottom of the bushing, the falling glass fiber is drawn out, and introduced into the first gathering shoe via an applicator roll. Here, a sizing agent is applied and focused, and the glass fiber for long fiber reinforced polypropylene resin molding material is wound by winding a paper tube set in a winder with a traverse wire through a second gathering shoe. Is obtained.

  The glass fiber drawn from the inside or the outside of the glass fiber roll is introduced into an impregnation die to which a molten matrix resin is supplied from an extruder, and the glass fiber is impregnated with the matrix resin. The glass fiber impregnated into the matrix resin is drawn through the die of the impregnation die. Excess matrix resin is removed by passing through a die, so that a predetermined glass fiber content can be obtained and a long fiber reinforced polypropylene resin molding material shaped into a predetermined shape can be obtained.

  Hereinafter, the present invention will be specifically described with reference to examples. However, these examples are illustrative of embodiments of the present invention and are not intended to limit the scope of the present invention.

[Test Example 1]
Examples 1-4 in which 4,000 glass fibers (2200TEX, manufactured by Asahi Fiber Glass Co., Ltd.) having a fiber diameter of 16 μm were converged and adjusted using the raw materials shown in Table 1 at the blending ratio (mass%) shown in Table 2. The bundling agent of Comparative Examples 1 to 5 was applied to obtain a wound body of glass fibers for a long fiber reinforced polypropylene resin molding material (hereinafter simply referred to as a glass fiber bundle).

  Using the evaluation apparatus as shown in FIG. 1 for the glass fiber bundle, the following procedure is used to pull the tension of the glass fiber bundles of Examples 1 to 4 and Comparative Examples 1 to 5, the amount of fluff, and the spread width (open state) ) Was measured.

(Measurement preparation)
a) Samples for evaluation (Examples 1 to 4 and glass fiber bundle wound bodies of Comparative Examples 1 to 5) 3 were set at specified positions.
b) The end yarns of the glass fiber bundle 4 were pulled out and passed through the pre-opening bar 1 and the pre-opening bar 2 supported on the table 5.
c) The glass fiber bundle 4 was passed through an unillustrated opening skewer in the opening BOX 6, and the end yarn of the glass fiber bundle 4 was put on the take-up device 7.
d) A predetermined weight was placed on the upper bar 8 of the opening skewer of the opening BOX 6 so as to be sandwiched between the upper and lower skewers, and a load was applied to the passing glass fiber bundle 4.
e) The take-up device 7 was started at a take-up speed of 20 m / min for a predetermined time.

(Tension measurement)
f) The take-up tension of the glass fiber bundle 4 was measured using a tension meter while the take-up device 7 was activated.

(Spread width measurement)
g) Subsequently, the width of the glass fiber bundle 4 passing through the opening skewer of the opening BOX 6 was measured with a caliper. Further, the opened state was visually observed.

(Fuzz amount measurement)
h) After taking a predetermined time, the fluff on the mesh in the opened BOX 6 sucked by the suction blower installed under the opened BOX 6 was collected, and the fluff weight was precisely weighed.

The results are shown in Table 3.

[Test Example 2]
The glass fiber bundles of Examples 1 to 4 and Comparative Examples 1 to 5 produced in Test Example 1 were mixed with a maleic acid-modified propylene resin having an acid value of 10 (mgKOH / g) and a homopolymer polypropylene resin (MI = 120). Was impregnated at a take-off speed of 14 m / min to obtain a long fiber reinforced polypropylene resin molding material of Examples 1-4 and Comparative Examples 1-5.

  The long fiber reinforced polypropylene resin molding material is cut into 8 mm, and the obtained pellets are subjected to injection molding using a long fiber injection molding machine and a multipurpose test piece mold under molding conditions in accordance with JIS-K6921-2. And a multipurpose test piece (JIS-K7139) was obtained.

Using the test pieces of Examples 1 to 4 and Comparative Examples 1 to 5, the glass content (based on JIS-K-7052), tensile strength (based on JIS-K-7161), bending strength (JIS-K-) 7171), flexural modulus (based on JIS-K-7171), IZOD impact strength with notch (test piece thickness 8 mm, based on JIS-K-7110). The results are shown in Table 4.

From the results of Test Examples 1 and 2, the weight and the average molecular weight of 10,000 to 20,000 an acid modified polypropylene resin (acid-modified polypropylene resin A), the acid modified polypropylene resin having a weight average molecular weight of 23,000～50,000 Glass fiber bundles (Examples 1 to 4) bundled with a sizing agent containing (acid-modified polypropylene resins B-1 and B-2) were excellent in fiber opening properties and workability was good. Moreover, the long fiber reinforced polypropylene resin molded article using the glass fiber bundle was excellent in mechanical properties, and the glass fiber was well dispersed and the appearance was good.

  On the other hand, when only an acid-modified polypropylene resin (acid-modified polypropylene resin A) having a small molecular weight is used as a sizing agent for a glass fiber bundle as in Comparative Example 1, the appearance is good due to good fiber opening properties, but it is somewhat fuzzy. This is easy, and the mechanical properties of the long fiber reinforced polypropylene resin molded product are also lowered.

  In addition, when an acid-modified polypropylene resin (acid-modified polypropylene resin C) having a large molecular weight is used as a glass fiber sizing agent (Comparative Examples 2 to 4), although workability and mechanical properties are improved, a propylene resin molded product is obtained. There were many undispersed glass fibers and the appearance was inferior. This is presumably because the unopened part of the fiber bundle is interposed in the propylene resin molded product because the fiber bundle is inferior in opening property because the convergence is too good.

  Furthermore, in Comparative Example 5 in which an acid-modified polypropylene resin having a weight average molecular weight of 23,000 to 50,000 was used alone, an unopened fiber bundle was likely to remain in the propylene resin molded product.

  The glass fiber for a long fiber reinforced polypropylene resin molding material obtained by the present invention is excellent in fiber opening property while maintaining sizing properties. In addition, the long fiber reinforced polypropylene resin molding material using the glass fiber for long fiber reinforced polypropylene resin molding material can provide good dispersion of glass fiber in the resin molded product, and propylene having excellent mechanical properties. A resin molded product can be provided.

It is the evaluation apparatus used for performance evaluation of the glass fiber for long fiber reinforced polypropylene resin molding materials prepared in the Example of this invention.

Explanation of symbols

1: Pre-opening bar 1
2: Pre-opening bar 2
3: Test sample installation position 4: Glass fiber bundle 5: Stand 6: Opening box 7: Pulling device 8: Upper bar

Claims (5)

Silane coupling agent (A), polypropylene resin having a weight average molecular weight of 10,000 to 20,000 (B), the weight average molecular weight containing a polypropylene resin 23,000~50,000 (C), A long fiber reinforced polypropylene resin molding material in which glass fibers are bundled with a sizing agent having a mass ratio of 20 to 80:80 to 20 between the polypropylene resin (B) and the polypropylene resin (C). Glass fiber. The are included in the sizing agent, the polypropylene resin having a weight average molecular weight 10,000 to 20,000 (B), polypropylene resin having a weight average molecular weight 23,000~50,000 (C) is 20 mass ratio It is 70: 80-30, The glass fiber for long fiber reinforced polypropylene resin molding materials of Claim 1. The length according to claim 1 or 2, wherein the polypropylene resin (B) having a weight average molecular weight of 10,000 to 20,000 is an acid-modified polypropylene resin and has an acid value of 40 to 50 (mgKOH / g). Glass fiber for fiber reinforced polypropylene resin molding materials.   The polypropylene resin (C) having a weight average molecular weight of 23,000 to 50,000 is an acid-modified polypropylene resin and has an acid value of 10 to 50 (mgKOH / g). Glass fibers for long fiber reinforced polypropylene resin molding materials as described in 1.   In the matrix resin which each single fiber of the glass fiber for long fiber reinforced polypropylene resin molding materials as described in any one of Claims 1-4 consists of polypropylene resin (D) and acid-modified polypropylene resin (E), A long fiber reinforced polypropylene resin molding material characterized by being contained in parallel in substantially the same length and in the same direction.

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